In recent years, many efforts have been made to reduce the fat content of various foods, such as salad dressing, sour cream and frozen desserts. When the fat level is reduced in conventional food products, however, the organoleptic properties are generally adversely affected because of the oiliness (lubricity) and slipperiness imparted by the fat particles suspended in the food product are removed.
Other mouthfeel and textural properties such as richness and creaminess may also be adversely affected by removal or reduction of fat. Polysaccharide and protein ingredients commonly known as fat mimetics have been used to restore some of the textural properties contributed by emulsified fats and oils, such as viscosity and gel strength. They have been used less successfully with respect to the more subtle mouthfeel factors. In addition, many of these ingredients have negative impact on flavor.
The FDA Standards of Identity recognize "reduced fat" foods as foods that have 25% less fat than the market standard of a full-fat counterpart of that food type. "Light" products retain 50% less fat than the market standard of a full-fat counterpart of that food type. "Low-fat" foods are defined as having less than 3 grams of fat per serving, and "fat-free" foods have less than 1/2 gram fat per serving. For purposes of this disclosure, the term "low-fat" is intended to include all of the above and will be used to describe the food products into which the present composition may be incorporated. In this disclosure, "low fat" is meant to include "reduced fat," "light," "low fat," and "fat-free" as defined by the FDA Standards of Identity for the sake of conciseness. However, the term "fat-free" is intended to include only "fat-free" as defined by the FDA Standards of Identity. In addition, the present invention is meant to include reduced-fat and fat-free food products that do not fall into the categories defined by the FDA Standards of Identity (as of the time of this disclosure), but deliver to the consumer reduced levels of fat per serving of a type of food.
As noted above, reduced-fat, light, low-fat and fat-free food products have been developed which duplicate the viscosity and other textural attributes of the missing fat by means of suitable food polymers, such as gums (xanthan or alginate), cellulose and its derivatives, starches and various microparticulated polymeric complexes. Unfortunately, flavor, mouthfeel and thermal factors are often adversely affected as compared to the full fat food products.
Many of these desirable attributes in full fat products are due to the presence of two distinct phases: an aqueous phase and an oil phase. The oil phase provides a reservoir of solvent for the flavor chemicals to dissolve in. By altering the proportions of the two phases, the partitioning of the flavor chemicals between the two phases is changed, affecting the character of the flavor and the way it is released in the mouth. In the extreme example of a fat-free product, the product consists of a single phase, and the flavor chemicals must be, of course, only dispersed in the aqueous phase. Free oil typically contributes to the mouthfeel of full fat products. In the mouth, some free oil separates from the bulk of the product, coats the mouth, and provides oily lubricity. Fats and oils also contribute thermal sensations in the mouth. These effects can be either mouthwarming as a result of the coating of the free oil, or mouthcooling due to melting of any crystalline fat.
The mesophase-stabilized emulsions and mesophase-stabilized dispersions which are provided by the present invention significantly improve the quality of reduced fat, light, low-fat and fat-free food products by providing some of the aforementioned attributes normally associated with full fat products. They do this by providing a separate phase, a mesophase, which is neither an aqueous phase nor an oil phase, but a liquid crystalline phase of both hydrophobic and hydrophilic character. They also provide a way of potentiating or maximizing the oily and fatty attributes of whatever oils or fats exist in the reduced fat, light, low-fat or fat-free product. By light microscopy, the mesophase-stabilized emulsions of this invention contain oil droplets which appear in a narrow range of particle sizes as relatively small-sized oil droplets dispersed in an aqueous gel phase. Upon centrifugation, most of the mesophase-stabilized emulsions of the present invention separate into an oil emulsion and a mesophase gel. In a food product, some of the oil droplets of the emulsion phase release their oil, providing lubricity, flavor delivery, and mouthwarming.
The mesophase gel of this invention provides stability and structure to the food product. Because starch components and other stabilizing or thickening agents are not required to structure the food product, maximum oily mouthfeel and flavor characteristics are retained. In fact, any fats or oils present in the mesophase-stabilized emulsions or mesophase-stabilized dispersions are potentiated by the present invention. The present invention represents a new method for making low-fat and fat-free food products by allowing highly viscous emulsions to be made regardless of the oil level, with no requirement for polymeric protein or polysaccharide thickening or bulking ingredients.
It is an object of the invention to provide mesophase-stabilized compositions for use in low-fat and fat-free food products which are superior to conventional low-fat and fat-free food products in the mouthfeel and textural properties which are experienced when consuming such food products. The attributes provided by the compositions of the invention are significantly better as compared to conventional low-fat and fat-free food products with regard to mouthfeel, flavor and textural factors.
It is an additional object of the invention to provide methods for making such mesophase-stabilized compositions for use in low-fat and fat-free food products. Food products containing these mesophase-stabilized compositions are superior to conventional low-fat and fat-free food products in mouthfeel, flavor and textural factors.